About the time Pam Ewing stumbled out of bed to find her "dead" ex-husband Bobby in the shower, one of her "Dallas" co-stars was slowly waking up to a disturbing realization of his own.

Dack Rambo, who is 50 and single, had found himself a new foe at Southfork: the entertainment industry's bias against men suspected of being gay--and consequently men suspected of having the AIDS virus.

"We were a few weeks into the show," Rambo said, "I noticed that the story line was veering off in another direction and I thought: 'What the hell is this?' All of a sudden my relationship with Priscilla (Presley, who played Bobby's girlfriend) was going right down the tubes.

"I knew there were whispers going on behind my back. Either 'He's gay,' or 'He's this or. . . .' And I thought, 'What the hell did I do?' People were just assuming. And people didn't really know anything about my private life."

That was 1985.

Actor Rock Hudson had just died of acquired immune deficiency syndrome, and Hollywood was still in a ruckus over his on-screen kisses with actress Linda Evans on "Dynasty," the decade's other prime-time blockbuster soap. The medical community had already established that the deadly disease was not transmitted by kissing, but unmarried male actors in their 30s and older were still suspect.

Now, six years later, has much changed? Could an actor known to have tested positive for HIV find employment?

"I think it would be pretty doubtful," said Rambo, who talked Friday about his new role as an AIDS spokesman and his old one as an actor. Rambo quit his role on the NBC daytime soap "Another World" in September, announcing that he had recently tested positive for the human immunodeficiency virus, which causes AIDS.

"And I think people are still pretty unknowledgeable about the disease and therefore fearful of employing anybody (with HIV). There might be some parts, but I don't think you would be doing any kissing scenes."

This fall the entertainment industry had to confront AIDS after Susan Bluestein made public a book proposal that her husband, 41-year-old actor Brad Davis, had written about his life as a secret AIDS patient. Brad Davis died in September. Davis wrote that while the industry gives its support through benefits and high-profile fund raising, it fails to support actors on an individual basis. Even those rumored to have HIV.

"I think there are certain people in town--people like (Fox Inc. chairman) Barry Diller and Hollywood Supports--there are people I think like that who are very dedicated to helping in whatever way," Rambo said. Hollywood Supports is a new ad-hoc organization created to solicit funds for people with HIV in the entertainment industry.

"But, yes, there are a lot of people who pay a lot of lip service to it, who pay in terms of money but don't really put themselves out there on the line. Obviously (Davis) felt that no one was out there for his particular cause. He kept it hidden because he was afraid he would never work again and (he wanted) to raise his child and to take care of his family."

Yet, where Davis found fear in disclosure, Rambo said he has found some peace.

"I feel so much better today having gone public with being HIV positive. It's like freedom to me. I've never felt better; some say I've never looked better in a long time. And I feel great. I don't have to think about (acting) any more. I want to devote my life to this, totally."

Rambo had joined the CBS prime-time soap "Dallas" in 1985 as Jack Ewing after Patrick Duffy left his role of Bobby Ewing.

"I was there about a week and realized I had made a grave error," Rambo said. "I think I didn't fit into the mold of what they felt was male or macho."

That season, the show slid from second to sixth place in the ratings and star Larry Hagman made a well-publicized personal appeal to Duffy to rejoin the cast. In one of the most celebrated cop-outs in soap opera history, the 1986 season opened with Pam Ewing finding ex-husband Bobby in the shower--and realizing she had dreamed the entire previous season.

But Rambo's bad dream at Southfork lasted another season before he departed: "There I was, kind of just wandering around either on horseback or on foot with no value to the show whatsoever."

Those dark days on "Dallas" haunted Rambo with each succeeding role, and he said he turned to prescription drugs to sleep, to calm his nerves--and for support.

"I was nervous about how I was going to be received or not received each time. It all became magnified in my mind, and it just became worse and worse. I look at some of the scenes on the screen today, and I look like I was just sort of sleeping through it--and I was."

Help came last year during a stay at the Betty Ford Clinic in Rancho Mirage.

"I was there about a day, two days, and I realized I had all the addictions: the pills, alcohol, sex--you name it. But it was all really enlightening to me."

Still, the actor who had kept his private life private for so long found that he was expected to share it at the center's group therapy classes.

"Every day I became more honest in talking about my sexuality, about being with men, about being with women and group sex and all of that. . . . Ever since that time, it hasn't been so hard for me to finally be just more and more honest with myself. And it's a good feeling.

"I think we all have (bisexuality) to some degree. And I think it varies in different times in our lives. I've been in love with men and I've been in love with women and deeply. . . . I think we all have that to some degree. And I think it varies in different times in our lives."

And while Rambo was coming to terms with himself, Hollywood was still having trouble facing up to the AIDS crisis.

Speaking out, Rambo said, is one of the keys to the AIDS battle. Former Los Angeles Laker Magic Johnson's revelation that he, too, has HIV helps the cause, Rambo said.

"Overnight, I think he was able to erase the stigma that people with HIV and AIDS have and raise the consciousness of the people. . . . He has made it easier for me too. He can make a great difference."

Still, he said, there are people who believe that AIDS is only a disease of "high-risk groups."

"It's almost like the heterosexual community wants to find (Johnson) gay, still doesn't believe that they can get it. They keep asking: 'Are you gay? Are you gay? Are you gay?' And he keeps saying: 'I'm not gay, I'm not gay, I'm not gay.' And--who cares? The issue is what he has."

Rambo is still adjusting to a life with HIV, still learning about it and still defining the role he will play as an activist. One decision he has made is to volunteer for AIDS Project Los Angeles. Through a staff of 140 and 2,400 volunteers, the organization serves about 3,200 clients--about 70% of the AIDS cases in Los Angeles County--with 20 programs and services.

"We are very fortunate that Dack has decided to come work with us," said Anthony Sprauve, the organization's director of communications. Rambo, Sprauve said, will primarily be helping in the areas of fund raising, education and public-service announcements, "but he has also expressed interest in working with clients."

Rambo also said he will be working with French virologist Dr. Luc Montagnier, one of the co-discoverers of HIV, and the Pasteur Institute in Paris in helping establish an international data bank for AIDS research.

"I've never lost somebody that I've been in love with, but I've lost somebody who was like a part of me," Rambo said, speaking of his twin, Dirk, who died at age 23 in an auto accident. The two farm boys from Earlimart, Calif., were discovered by Loretta Young while sitting in a pew of a Los Angeles church. The actress cast them in her 1962 TV series. "It's like losing a limb. It's like being part of the same person. I loved my brother very much.

"Do I still talk to him? Yes, I do. I ask him to help me once in a while.

"I've asked him to give me strength, to cope with (HIV) and to not look at it in such a terrible way as I may have done before, but to use it whatever way I can to the good."